Mica sorting apparatus



June 13, 1933'. L. T. FREDERICK MICA SORTING APPARATUS Filed June 22, 1928 2 Sheets-Sheet 1 June 13, 1933. T. FREDERICK MICA SORTING APPARATUS Filed June 22, 1928 2 Sheets-Sheet aeyzz ora' Jonas i Patented June 13, 1933 omreo STATES,

PATENT? OFFICE LOUIS T. FREDERICK, 0E VALPARAISO, INDIANA, ASSIGNOR, BY MES'NE ASSIGNMENTS,

T0 CONTINENTAL DIAMOND FIBRE. COMPANY, OF NEWARK, DELAWARE, A COR- PORATION OF DELAWARE MIcA s'onarue APPAnA'rUs Application filed June 2 2,

My invention relates in general to mica treating apparatus and methods and has more particular reference to ways and means for splitting up and separating blocks of raw mica into their constituent laminations and separating the laminae or flakes of mica into grades according'to their thickness, it being well known in the art that, forcertain manufacturing purposes, it is advantageous to use mica flakes of uniform thickness. More specifically, my invention relates to means and method of splitting up raw mica into flakes of uniform thickness and depositing those flakes as a uniform layer to form a sheet of mica flakes of substantially uniform thickness.

I have discovered that blocks of raw mica may be conveniently split into their con stituent laminations by means of a process involving heating the mica, suddenly quenching the heated mica in a liquid bath and thereafter drying the quenched mica by applying heat. The first heating. causes the mica to puff and to separate slightly'along its lines of cleavage. The sudden quenching, when in this puffed condition, allows moisture to enter between the laminations and the subsequent evaporation of the moisture tends to furtl. er separate'the laminations. I have discovered that by snowing mica, treated in this manner, through a tumbling screen which tumbles the mica flakes about and tends to further separate the laminations and which releases the mica flakes in the form of a cloud, the particles or flakes of which fall downwardly under the influence of gravity, I am able to separate a substantially uniform grade of mica flakes from the. mica cloud by arranging a suction separating apparatus adjacent thereto whereby the lighter flakes may bewithdrawn from the stream of flakes comprising the cloud, theheavier flakes continuing downwardly into a depository from which they may be removed for further treatment or retreatment.

Ordinarily, after having heated, quenched and dried the mica, it is suflicient tosubject the thicker mica, which has not been separated bythe suction separator, to a repetition of the tumbling and snow g P 1 it 1928. Serial No. 287,503.

being unnecessary to repeat the heating,

quenching and drying process. This is true for certain grades of raw mica and particularly so if the mica has been subjected to a weathering action before I being treated. However, I may repeat the heating, quenching and drying process whenever necessary.

I have found,- however, that certain grades of mica may be more economically reduced to their constituent laminations if, in addi tion to the heating, quenching and snowing processes heretofore mentioned, they are subjected to a mechanical crimping process such as may be accomplished by the mica splitting apparatus illustrated in my co-pending application, Serial. Number 157 ,804, filed December 29, 1926.

a One of the objects of my present invention is toprovide an apparatus for splitting, separating and sorting mica which is adapted to include, in a single machine, the various methods heretofore mentioned, it being understood that where it is unnecessary to use any step of a process, it is not economical to use such step but that a shorter process which omits such step and, which yet is satisfactory in separating and; sorting the mica, is more desirable' The average grade of raw mica available, however, makes it necessary to provide the more complete means for splitting and separating the mica into its con stituent laminations.

Another important object of my present invention is to providea means for separating the lighter mica laminations from a stream of mica flakes by means of pneumatic suction.

Another important object of my present invention is to provide a means for separating the lighter mica flakesby means of suction operating against the force of gravity.-

,7 Numerous other objects and advantages of the invention will be apparent as it is more fully understood from the description which, taken in connection with the accompanying drawings, discloses a preferred embodiment of the invention. 4 Referring to the drawings: r

I Figure 1 is a perspective, View showing, in a somewhat diagrammatic manner, the ar rangement of the various parts of the apparatus of my invention;

Figure :2 is a schematic elevation of the apparatus illustrated in Figure 1, parts of which are shown in cross section to reveal the details of construction; and

Figure 3 is a modification of the suction separator whereby the same may be utilized as a mica laying machine. 10

To illustrate my invention I have shown in the drawings an apparatus for splitting and separating raw mica into its constituent laminations and sorting the laminations into substantially uniform grades. The apparatus illustrated comprises a heating oven 11, a quenching bath 13, a drying oven 15, a snowing apparatus 17, a suction separator 19, a tumbling drum 21, a crimper 23 and means for conveying the mica through these various parts. A continuous conveyer 25 extends through the heating oven ll. This conveyer is carried on spaced rollers 27 and has an upper stretch upon which the raw mica may be deposited at one end through a hopper 95. This mica is carried through the oven 11 by the movement of the conveyer 25 and is discharged from the opposite end of the conveyer onto the submerged end of a second continuous conveyer 29 which passes around spaced rollers 31, one of which is immersed in a quenching bath 33. The heated mica is discharged into the quenching bath and falls upon the submerged'portion of the conveyer 29. The mica is withdrawn from the quenching bath by the movement of the conveyer 29, is carried thereby through the drying oven 15 and is discharged at the opposite end of the conveyer into a third conveyer 35 comprising an endless chain of mica buckets 37. This conveyer is adapted to raise the mica to a point at which it may be discharged into a chute 39 emptying into a snowing screen 41 which comprises a part of the snowing device 17 heretofore mentioned. The conveyer 35 is carried by rollers 43 which maintain the conveyer in a predetermined path. The mica buckets 37 may be conveniently formed of sheet metal and suspended between spaced chains 45 carried by the rollers 43 which may be in the form of sprockets.

The snowing apparatus 17 comprises a foraminated snowing screen 41 comprising a cylindrical rotatable member formed of wire mesh or other suitable foraminous material. The snowing screen is open at its forward end to receive the discharge end of the chute 39 through which mica flakes may be introduced into the center of the cylindrical snowing screen or tumbling drum. The screen or tumbling drum is mounted for rotation at the upper end of a chute 43 formed of sheet metal arranged to define a channel or chamber in which a cloud of mica flakes may be produced upon rotation of the snowing screen. The channel is provided with kickers 45 comprising members carried on a rotatable rod journaled in the sides of the chute and which, upon rotation of the rod, kick the flakes about in the channel thus agitating the cloud of flakes as it passes through the chute and assisting in further splitting up the mica laminations. The chute 43 leads to the suction separator 19. The wall of the channel or chute 43 is cut away as at 47 to provide an opening over which a suction device or hood 49 is arranged. A continuous foraminated screen 51 is arranged to guide the screen 51 across the suction device 49, the screen passing between the apertured wall of the chute 43 and the suction device. As the cloud of mica flakes passes through the chute 43 it is deflected toward the suction device 49. Means (not shown) preferably comprising an exhaust pump, is attached to the suction hood for the purpose of drawing a current of air through the suction device and screen 51. This current of air attracts the flakes and tends to draw them onto the inner surface of the screen as it passes across the mouth of the suction hood. The force of gravity and the momentum of the flakes in falling through the chute, however, tends to draw the flakes away from the screen and the current of air is not sufficiently strong to maintain the heavier flakes upon the conveyer, such flakes as are retained upon the conveyer being the lighter, thinner flakes. A continuation 55 of the side wall of the chute extends downwardly below the suction device and the upper edge of this continuation is spaced inwardly of the edge of the suction device. As the screen 51 passes across the suction device in the direction indicated by the arrow in Figure 2, it acts as a conveyer to carry the light, thin flakes which are adhering thereto over the upper edge of the wall 55 and out of the chute. When the conveyer passes beyond the influence of the air draft created by the suction device, the light, thin flakes, being released from the force of the air draft through the conveyer, will detach and fall into a chute or receptacle 57 conveniently arranged beneath the conveyer to receive the flakes. Beneath the suction device, the walls of the chute 43 may be provided with a plurality of apertures 59 to assist in agitating the cloud of mica flakes and to allow the draft of air created by the suction hood to act with maximum efliciency in separating and drawing the lighter flakes onto the conveyer. The lower end of the chute 43 is arranged to dis charge the heavier flakes, that is to say the flakes which are not withdrawn from the chute by the conveyer 51 and suction device onto a conveyer 61, similar in construction to the conveyer 35 heretofore described and provided with mica carrying buckets 63 similar to the buckets 37 attached to the conveyer 35. The conveyer 61 carried on guide rollers 69. The upper end of this chute is arranged in the form of a hopper 67 and the conveyer 63 is arranged to carry the heavier or unseparated mica flakes discharged at the lower end of the chute 13 and to deposit them The transfer chute is pro of which the chute is adapted to convey the mica flakes deposited in the hopper at 1ts upper end to either of three points 1n the separating and sorting apparatus. One arm 73 of the transfer chute leads to the hopper 95 at the receiving end of the conveyer 25 and when the control shutter governing this arm of the transfer chute is arranged to deflect mica from the hopper 67 into the armc73, the mica will be re-subjected to the heatlng, quenching and drying process. A second arm 75 of the transfer cl ute is arranged to convey the mica to a tumbling drum 21 and a crimper 23 when the control shutters 71 are properly set. The tumbling drum compr ses a rotatable cylinder which in the present instance is carried on rollers 77 and which is driven by means of a belt 79 from a motor 81'.

r This drum is for the purpose of tumbling the mica blocks about and thereby loosening the mica laminations. The drum is ar ranged to discharge the tumbled mica into the crimper 23 which combines a pair of belts 83 carried around spaced rollers 85 andhaving adjacent contiguous stretches arranged to pass in a serpentine manner between spaced formers 87 which may either be rollers or stationary members. The construction of the crimper 23 is described in detail in my co-pending application, Serial No. 157 ,894, filed December 29, 1926. The mica is deposlted by the discharge nozzle 89 of the tumbling drum onto the upper stretch of the lower conveyer 83 and is carried between the contiguous stretches of the conveyers 83 along a serpentine path between the formers 87 and is discharged from the opposite end of the upper stretch of the lower conveyer 83 onto the conveyer 85 whence the crimped mica is raised and re-deposited into the chute 39 leading into the tumbling screen 41 and is again subjected to the snowing and separating action of the snowing device 17 and the separating device 19. V

The transfer chute 69 has a third arm 91 which, when the shutters 71 are properly set, conveys the mica directly from the hopper 67 onto the conveyer 35 which re-deposits the mica into the inlet chute 39 of the snowing device'17 so that the snowing and separating process may be repeated. I have illustrated in Figure 2 of the drawings a modification wherein this third arm 91 of the transfer chute 69 extends directly into the inlet chute 39 so that the conveyer 35 is relieved of conters Patent is 7 'said opening. a

gestion and may be used for the purpose of bringing in a second batch or lot of mica, thus increasing the capacity-of the machine; The suction separator 19 which I have ilf lustrated is a preferred embodiment'and it will be understood that any convenient form of suction separator may be exchanged for the form illustrated without departing from the spirit and scope of my invention in its broadest aspect. The suction separator or mica sorting device 19 is a preferred embodiment of an invention first disclosedin my co-pending applications, Serial Numbers 139,288, filed October 2 and 4, 1926.

In Figure 3 of the drawings I have illustrated a preferred modification in which the separated flakes are deposited upon-a conveyer 93 which may be the-receiving coniveyer of a mica laying machine and by means of which the flakes selected by the separator 19 may be immediately layed up in the'form of a mica plate and secured together by means of a suitable binder sprayed upon the flakes as they lie on the conveyer, the conconvenient or preferred form.

It is thought that the invention and numerous of its attendant advantages will be apparent from the foregoing descriptionand it will be apparent that variousichanges may be made in the form, construction and arrangement of the various parts without departing from the spirit and scope of the invention or sacrificing any of its attendant advantages,- the form hereinbefore described being a preferred embodiment for purposes of illustration. l

I do not claim herein the broad subject matter of invention set forth and claimed in my co-pending applications, Serial Number 139,219, filed October 2, 1926, l and Serial Number 290,951, filed July 7, 1928.

Having thus describedimy invention, what I claim as new and desire to secure by Let 1. In a mica treating apparatus, the combination of a housing forming a chute, means for snowing a cloud of mica flakes into the chute, whereby the same may travel downwardly therein under the influence of gravity, said chute having an opening in its "member, whereby to draw mica flalres'toward the foraminated member, said chute having perforations in its walls oppositesaid open- 7 ing, whereby to admit drafts of air into the chute to agitate the flakes in the vicinityof 12; In a mica treatlng appara-tus, the combinatio rof a housing form ng a chute inv. cludingan' upwardly extending section and a laterally extending section, a rotatable cylindrical screen arranged in the upper portions of the chute, whereby mica flakes fed into the screen will be snowed into the chute in the form of a cloud, said chute being arranged to permit the said cloud to travel downwardly therein under the influence of gravity, the lower portions of the chute havingran opening in the walls thereof, a continuous flexible air pervious screen mounted with a stretch extending across said opening, said screen being guided to travel across said opening, and said chute and the opening therein being so arranged that the screen portion exposed to the interior of the chute at said opening is out of the direct path of the falling cloud of mica flakes, suction means arranged behind said travelling screen in position to draw a current of air through the portion of the screen exposed to the interior of the chute at said opening, whereby to draw mica flakes onto the screen and means for shifting the screen so as to carry the flakes adhering thereto out of the chute and" away from the zone of influence of the suction device, whereby the flakes will be released at a remote point outside of the chute, said chute being arranged so that the opening extends substantially horizontally with the portion of the screen exposed in the opening facing downwardly, the lateral section of the chute being formed to project the falling flakes laterally under the downwardly facing screen whereby the flakes may be sorted by the differential action of the suction exerted through the screen and the force of gravity operating on the falling flakes of the cloud.

3. In a mica treating apparatus, the combination of a housing forming a chute, a rotatable cylindrical screen arranged in the upper portions of the chute, whereby mica flakes fed into the screen will be snowed into the chute in the form of a cloud, said chute being arranged to permit the said cloud to travel downwardly therein under the influence of gravity, the lower portions of the chute having an opening in the walls thereof, a continuous flexible air pervious screen mounted with a stretch extending across said opening, said screen being guided to travel across said opening, and said chute and the opening therein being so arranged that the screen portion exposed to the interior of the chute at said opening is out of the direct path ofthe falling cloud of mica flakes, suction means arranged behind said travelling screen in position to draw a current of air through the portion of the screen exposed to the interior of the chute at said opening, whereby to draw mica flakes onto the screen and means for shifting the screen so as to carry the flakes adhering thereto out of the chute and away from the zone of influence of the suction device,whereby the flakes will be released at a remote point outside of the chute, said chute being arranged so that the opening extends substantially horizontally with the portion of the screen exposed in the opening facing downwardly, the chute being also formed to project the falling flakes laterally under the downwardly facing screen whereby the flakes may be sorted by the differential action of the suction exerted through the screen and the force of gravity operating 'on the falling flakes of the cloud, said chute being also provided with a plurality of perforations in its walls opposite the opening whereby air may be drawn into the chute in the vicinity of the suction device in order to create turbulence in the cloud of mica flakes.

4:. In a mica treating apparatus, the combination of a housing forming a chute including an upwardly extending section and a laterally deflected section at the lower end thereof, means for creating a cloud of mica flakes in the chute whereby the same may travel downwardly therein under the influence of gravity, the laterally deflected section of the chute having an upwardly facing opening in its walls, a foraminated member extending across said opening, means for creating a draft of air through said opening and the foraminated member whereby to draw mica flakes upwardly toward and onto the foraminated member, and means to shift the foraminated member with the flakes adhering thereto to remove the flakes through the openmg.

5. In a mica separating apparatus, the combination of a downwardly facing suction device, a foraminated member extending across the lower surface of the suction device, a compartment including a section extending substantially horizontally with an opening at the upper portion thereof aligned under the suction device and exposed to the foraminated member, means to create a cloud of mica flakes in said chamber whereby certain of the lighter flakes of the cloud may be drawn upwardly against the underside of the foraminated member, and means to shift the foraminated member to carry the flakes adhereing thereto out of the compartment.

In witness whereof, I have hereunto subscribed my name.

LOUIS T. FREDERICK. 

